Survey: SIP Trunking on the Rise

Enterprises are becoming increasingly aware of the costand otherbenefits of bypassing the PSTN with their VoIP traffic.

SIP trunking is on the rise, challenging traditional techniques for linking internal VoIP networks with outside telephone networks, a new study finds. Although T-1 lines still lead as the most common trunking service, by 2010 SIP trunking (a direct connection from an organization's IP PBX to the Internet telephony service provider, bypassing the PSTN) will be the second most common trunking type, according to Infonetics Research.

"Many companies have deployed VoIP internally, but they usually use legacy TDM technologies to connect to the PSTN," said Matthias Machowinski, Infonetics Researchers directing analyst for enterprise voice and data. The findings are part of a new report: SIP Trunking Deployment Strategies: North American Enterprise Survey, which asked 92 North American organizations with 101 or more employees about how they choose a SIP trunking service, how they use them, and how much they are spending on such services.

SIP trunking is expected increasingly to challenge the traditional technology for linking internal VoIP networks with the outside. "SIP trunking is catching up with TDM services and gaining broad traction with buyers, driven by their desire to lower their overall trunking expenditures," Machowinski said.

One roadblock remains: timing.

"It is unlikely well see a rush toward SIP trunking, as SIP trunks are usually implemented during general technology upgrades, which are on hold at many companies right now," the analyst said. Although spending has slowed, it hasnt totally stopped for trunking. Companies spend between $100,000 and $500,000 per year on trunking services, the survey found.

As for SIP trunking, interest is growing beyond simple curiosity. Infonetics Research found 39 percent of the companies surveyed reported deploying SIP trunks. Additionally, SIP trunking was described as being deployed widely rather than in limited trials of one or two sites.

Earlier this year Infonetics announced it expected SIP trunking revenue to hit 89 percent compound annual growth through 2013.

As the growth of SIP trunking continues, so increases demand for session border controllers, or SBCs. The SBC acts as a traffic cop and translator between a companys internal VoIP network and the outside telephone network.

"The enterprise SBC market is driven by the general adoption of SIP trunking services, and more specifically by large enterprises looking to SIP trunking services as a way of consolidating, centralizing, and increasing the utilization of their trunking infrastructure," Infonetics analyst Matthias Machowinski said earlier this year. Infonetics sees the enterprise SBC market growing 49 percent annually through 2013.